Spongy pedal

[Graham]

Hi, after a long overhaul and various machining done i fit my bremsport callipers and AP discs. I have nailed the pedal and havent noticed any leakage yet (touch wood). I took it out for a run and the pedal feels spongier than the original callipers. I flushed the system with a bottle of dot 4 for now to see if all is ok then in a few weeks i am putting in the 5.1.
With these callipers having 4 pots does this require more pedal travel to provide more fluid? Or am i missing some thing. if i have any more problems with these callipers i still realy like the sound of coreys porsche setup, how much would this cost? for callipersa discs pipes and fittings?
Cheers
Graham

[dan_b]

You shouldn't feel sponginess in the pedal from having more pots - what you should feel is that you will need more pedal effort initially as you're having to act on a greater total surface area to move the additional pistons, and the servo assistance hasn't become any greater.
Sponginess is usually a sign of air in your brake system somewhere - give it another bleed.

I had exactly this when I did my brake upgrade in January, my pedal was spongy, which put down to there being more pots, but I since have bled the front calipers twice more and got an alarming amount of air out each time, and each time the pedal got much firmer. I now have a really solid pedal feel, which is great.

In short - try bleeding again!

[Graham]

Thats all i could think of, if i hadnt gotton all the air out and with them having so many places air could hang in. I will drive it for a week and re-bleed next week.
Cheers, Encourages me a bit. With all the work i have done to bring these up to "as new" condition. (they were a bargain of course). I hope that is all it is.
Graham

[Stick Insect]

Graham,

I don't know what you used to bleed the brakes but I can highly recccoment the Gunson Eezibleed is a fantastic help. It flushes the bubbles out more easily than pumping with the foot pedal.

I know you have only done your fronts but bleed the backs as well. Start with the longest run and work towards the shortest NSR to OSF usually.

David

[Beetie]

If its still the same when you get to GTI international, ill give you a hand bleeding them, it shouldnt take five minutes.....
Then again knowing s2's itll be about three hours!

[Dr H]

Graham

Got any pics of the brakes?

[Beetie]

Originally posted by LPHUK2002
Graham

Got any pics of the brakes?

Good point! I wonder if they have two bleeding points? Has anybody else gone with the bremsport calipers or is Graham the first?

[Graham]

Hi here is the pics i took, i only took 2 as i just wanted to get them on and tested.:

[Graham]

And here is a close up of the calliper:

[dan_b]

My porsche calipers have two bleed valves per caliper - one on each side. I was surprised how much air came out of both bleed valves, you'd have thought that bleeding one would drag all the air from that side, but no! Check your calipers, I'd be surprised if there weren't two also.

I can recommend the Gunson's thing for doing a fluid change, that's how I did mine, but the last two times I bled it I just did it with gravity.

What brake fluid have you got? I went for the Halfords DOT 5.1, I'll probably go for one of the uber-fluids next time, but it seems effective enough.

[Graham]

Yes there is 2 bleed nipples on each calliper. One on each bank of pistons, i get my new clutch master cylinder bits this week off Martyn, so next Saturday when i fit them i will re-bleed the brakes. Also, where does the gunsons pressure bleeder get its perssure from i think i might have to buy one. With all the work i have done on the brakes i am having a 6 week trial period to iron out any problems i might have. In a few weeks i put in the 5.1 fluid in. Dont think it is an expensive one just one from the motor factors.
Graham

[dan_b]

Gunson's device gets its air pressure from your spare tyre (if you have one!). They say to not exceed a pressure of 20psi IIRC. Essential to make sure that the fluid reservoir on the Gunson has plenty of fluid in it and remains vertical at all times so that you don't risk pushing air actually in to the system!

You can get the Gunson's from Halfords, it's about £15 IIRC, well worth the money as it's a real time-saving piece of kit - I did a complete fluid change and bled all 6 bleed valves in about 30mins with it.

Let us know how you get on!

[Graham]

Cheers will do. Thanks for the info on the tester.
Graham